Decreasing load deflection mechanism

ABSTRACT

In the preferred embodiment there is a loading mechanism for providing an initial load on a magnetic card in a card hopper such that when the magnetic card is brought into contact with a feed roller, the card is fed from the card hopper. This mechanism includes a flat permanent magnetic strip mounted on the frame of the card hopper and a steel blade having one end pivotably mounted on the frame. The steel blade is magnetically attracted to the magnetic strip. The other end of the steel blade is attached to a pressure plate resting on the top card in the hopper. When a given number of cards are in the hopper, the steel blade is completely out of contact with the magnetic strip. At this time, the only weight applied to the drive roller is the weight of the cards plus the weight of the pressure plate. As cards are fed from the hopper, the steel blade is lowered into contact with the magnetic strip. The initial contact is adjacent the blade pivot point. As additional cards are fed, the contact area of the blade and spring increases incrementally in a rolling type manner such that the combination of the permanent magnet, steel blade, and pressure plate imparts an increasing downward pressure on the stack of cards to thereby off set the weight decrease resulting from the feeding of cards to provide a fairly uniform weight on the card drive roller which varies within acceptable limits such that reliable card feeding of all the cards in the hopper is accomplished.

Unite States Patent 1191 Kroeker Mar. 4, 1975 Elmer Leroy Bob Kroeker, Austin, Tex.

[73] Assignee: International Business Machines Corporation, Armonk, NY.

22 Filed: on. 31, 1973 21 App]. No.: 411,591

[75] Inventor:

[52] US. Cl 271/160, 271/DIG. 3, 271/126,

271/165 [51] Int. Cl. B65h 1/06, B651 3/16 [58] Field of Search 271/126, 127, 147, 157,

271/160, 22-25, DlG. 3, 181, 30,31,149, 165,109,110,114,121,122,128130,193; 221/56,57,212

Primary Examiner-Evon C. Blunk Assistant E.\'aminerRobert Saifer Attorney, Agent, or Firm-John L. Jackson 57 1 ABSTRACT In the preferred embodiment there is a loading mechanism for providing an initial load on a magnetic card in a card hopper such that when the magnetic card is brought into contact with a feed roller, the card is fed from the card hopper. This mechanism includes a flat permanent magnetic strip mounted on the frame of the card hopper and a steel blade having one end pivotably mounted on the frame. The steel blade is magnetically attracted to the magnetic strip. The other end of the steel blade is attached to a pressure plate resting on the top card in the hopper. When a given number of cards are in the hopper, the steel blade is completely out of contact with the magnetic strip. At this time, the only weight applied to the drive roller is the weight of the cards plus the weight of the pressure plate. As cards are fed from the hopper, the steel blade is lowered into contact with the magnetic strip. The initial contact is adjacent the blade pivot point. As additional cards are fed, the contact area of the blade and spring increases incrementally in a rolling type manner such that the combination of the permanent magnet, steel blade, and pressure plate imparts an increasing downward pressure on the stack of cards to thereby off set the weight decrease resulting from the feeding of cards to provide a fairly uniform weight on the card drive roller which varies within acceptable limits such that reliable card feeding of all the cards in the hopper is accomplished.

9 Claims, 4 Drawing Figures DECREASING LOAD DEFLECTION MECHANISM BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to spring mechanisms in genera], and more particularly, to a spring type mechanism in which as the spring work length is extended, the amount of force applied by the spring mechanism decreases as distinguished from the usual extension spring in which as the extension spring is extended, the load applied by the extension spring increases.

2. Description of the Prior Art In the IBM Mag Card II system, there is included a hopper which can hold from one to fifty cards. These cards are fed by activating a feed magnet which allows the bottom card in the hopper to come in contact with a constantly rotating drive roller to feed the card into a read/write station. To assure proper feeding of the last card in the hopper, the IBM Mag Card II had an initial loading of ten ounces. This initial loading was used since it was found that in controlled environments, the normal force to cause reliable card feeding is 8 ounces. This initial loading was by means of an extension spring which was connected to the frame of the hopper and to a pressure plate resting on the card stack. As additional cards were added, this extension spring applied more and more force to the pressure plate with a consequent increase in force on the drive roller. There was a practical limit as to the number of cards which could be accommodated by this type of system. This number was approximately 50. That is, the load on the drive roller increased as a function of the loading spring rate plus the increasing card weight. Thus, the maximum number of cards which could be accommodated was 50.

In many applications there is a need for more than a 50 card hopper capacity. However, with the system of the IBM Mag Card II, its hopper capability could not be expanded to, for instance, 140 cards due to the fact that the extension spring added more and more pressure as the height of the stack of cards increased, coupled with the fact that the weight of the cards was increasing. The problems presented, if the IBM Mag Card ll system were used with a 140 card capacity hopper, are that the relatively high card weight would result in great wear between the cards and in addition, the electro-magnet and spring arrangement which causes feeding, which will hereinafter be described in detail, would have to be redesigned since the electromagnet works against a card lifter spring to drop the stack of cards onto the drive roller for feeding. Obviously, the spring which holds the cards off of the drive roller would have to be increased in strength, which would necessitate a larger and more powerful electromagnet to overcome the spring force when there is a relatively small number of cards in the hopper.

Another problem presented with respect to the Mag Card II system is that the initial loading was only ten ounces. Ideally, to assure better feeding of the cards, the normal force on the drive roller, to accommodate a wide range of environmental conditions, should be greater and should be around 14 ounces. With the Mag Card II system however, the addition of the 4 ounces for initial loading would result in too much force being applied to the drive roller when the hopper was full. Thus, the initial loading was less than desirable for reliable feeding under certain conditions.

SUMMARY OF INVENTION In the preferred embodiment there is a loading mechanism for providing an initial load on a magnetic card in a card hopper such that when the magnetic card is brought into contact with a feed roller, the card is fed from the card hopper. This mechanism includes a flat permanent magnetic strip mounted on the frame of the card hopper and a steel blade having one end pivotably mounted on the frame. The steel blade is magnetically attracted to the magnetic strip. The other end of the steel blade is attached to a pressure plate resting on the top card in the hopper. When a given number of cards are in the hopper, the steel blade is completely out of contact with the magnetic strip. At this time, the only weight applied to the drive roller is the weight of the cards plus the weight of the pressure plate. As cards are fed from the hopper, the steel blade is lowered into contact with the magnetic strip. The initial contact is adjacent the blade pivot point. As additional cards are fed, the contact area of the blade and spring increases incrementally in-a rolling type manner such that the combination of the permanent magnet, steel blade, and pressure plate imparts an increasing downward pressure on the stack of cards to thereby off set the weight decrease resulting from the feeding of cards to provide a fairly uniform weight on the card drive roller which varies within acceptable limits such that reliable card feeding of all of the cards in the hopper is accomplished.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a cut-away side view of the subject inverse spring loading mechanism with a small number of cards in the hopper which results in the magnetic strip and steel blade being in contact substantially along its entire length;

FIG. 2 is a cut-away side view of the mechanism of FIG. 1 with a larger number of cards in the hopper to illustrate the pulling away of the blade from the magnet;

FIG. 3 is a partial side view of the mechanism of FIG. 1 with the hopper fully loaded illustrating the complete separation of the steel blade from the permanent magnet;

FIG. 4 is a plot of curves representing the force applied at the feed roll verses thenumber of cards with the total force being broken down into card weight at the feed roll; blade; permanent magnet and pressure plate load.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT For a detailed description of the drawings, refer first to FIG. 1. In FIG. 1 the numeral 1 designates the frame of the hopper. The frame is cut-away and is represented at various points by slashes as indicated at 1. The frame in the other figures is also represented in a similar manner.

In FIG. 1 there is shown a stack of cards 2 which are resting at their right most extremity on a first section 23 of a base plate and are held above the second section 3 of the base plate by means of a card lift roller 9. Card lift roller 9 is rotatably mounted on shaft 8 which is supported at its left most extremity by the frame and hearing mount 11 mounted thereon. T-shaped member 7 is rotatably connected to bearing mount 11 by means of shaft 10. Thus, T-shaped member 7 is rotatable around member 7. The other end of shaft 10 includes a slot 17 to which is connected to one end 18 of card lift spring 19 which has its other end 21 wrapped over a pin 20 which is an extension of mounting 22 which is connected to the frame of the card hopper. Also connected to T-shaped member 7 is an actuator 12 by means of shaft 13. Again, this is a pivotable connection. Connected to actuator 12 is an armature 14 which upon application of a potential to winding 16 wrapped on core will cause application of force to T-shaped member 7 to overcome the spring force of card lift spring 19 to thus allow the bottom card in the hopper to drop onto drive roller 4 which is constantly rotating in the direction indicated by the arrow associated therewith. This constantly rotating drive roller is driven by motor means and suitable gearing (not shown). When a card drops onto the drive roller, it is driven by the drive roller out through opening 25 which is formed by means of a gate member 24 which is attached to the frame of the card feed mechanism. Other drive means (not shown) then drive the card into a read/write area (again not shown).

Resting on top of the cards is a pressure plate 26. Pressure plate 26 includes a handle 27 which is utilized by the operator to lift up the pressure plate for insertion of cards. Pressure plate 26 also includes a roller 28 mounted thereto bymeans of shaft 29 for rolling movement across the top card. Also attached to pressure plate 26 is T-shaped member 31 having an extension 31a pivotably connected to pressure plate 26 by means of shaft 30. The T-shaped member 31 is pivotably connected to the frame of the card hopper by means of bearing mount 34 and pin 35 mounted in bearing mount 34. Thus, T-shaped member 31 is rotatable around shaft 35. Attached to T-shaped member 31, also at shaft 35, is a steel blade 32 having its other extremity attached to the T-shaped member 31 at point 36. Point 36 can either be a slot or can include a protrusion on which steel blade 32 applies pressure.

Also mounted on the frame 1 is a permanent magnet strip 33 which attracts steel blade 32. As shown in FIG. 1, the blade is almost in complete contact with the magnet 33 and due to its flexure is applying an initial force of approximately 14 ounces.

Shown in FIG. 2 is a larger number of cards and this illustrates the peeling away of blade 32 from magnet 33.

Finally, as shown in FIG. 3, there is approximately 140 cards in the hopper and the steel blade 32 has been completely released from magnet 33 and is not applying any pressure to pressure plate 26. Thus, the effective weight applied to the drive roller during feeding would be the weight of the cards plus the weight of the pressure plate.

With this type of arrangement, the system can be ini tially loaded such that with a single card in the hopper, 14 ounces is applied which will assure proper feeding in most environmental conditions and the loading applied to the cards by the blade-magnet combination, assuming a full load of cards in the hopper, increases from zero to a maximum of 14 ounces as the cards are fed from the hopper. This type of arrangement assures a fairly uniform force being applied to the drive roller which results in, as compared to an arrangement where an extension spring is utilized in reduced friction between the cards; lower electrical power requirements for the feed magnet; lower pressure plate forces which assists the operator in inserting additional cards into the hopper; a smaller band or range of loading forces which is desirable for adverse environmental conditions; fewer variables in the loading forces as the card number increases or decreases; greater manufacturing tolerances on the associated parts; and low cost materials.

In FIG. 4 there is shown a plot of the normal force applied to the feed roller verses number of cards. It will be seen from FIG. 4 that the initial force applied where there are no cards in the hopper is approximately 14 ounces. This force is totally from the pressure plate load plus the force applied by the blade and permanent magnetic strip. As cards are added, it can be seen that the blade and permanent magnet as they are peeled apart, result in less force being applied by them while the card weight goes up. As shown in the drawing of FIG. 4, at approximately cards with this type of arrangement, the blade and permanent magnet totally separate and the force applied to the stack of cards is solely that of the pressure plate weight. From a further consideration of FIG. 4, it can be seen that the net load applied to the drive roller for zero to 140 cards varies only from 14 ounces to approximately 24 ounces. This limited ten ounce variation in net load could not be achieved through use of the extension spring utilized in i the Mag Card II packfeed system.

For the particular system plotted, the steel blade was spring steel 0.016 of an inch thick, 8 inches in length, and /2 inch in width. The magnetic material was PLAS- TIFORM 1-H and was 0.125 inch in thickness and /5 inch in width and of a length substantially equal to that of the steel blade, but varying slightly as illustrated in the drawing. The drive roller in the IBM Mag Card II is made of vibrathane B-605, while the magnetic cards are standard magnetic cards. Their make-up is described in US. Pat. No. 3,617,378.

In summary, in the preferred embodiment there is a loading mechanism for providing an initial load on a magnetic card 2 in a card hopper such that when the magnetic card is brought into contact with a feed roller 4, the card is fed from the card hopper. This mechanism includes a flat permanent magnetic strip 33 mounted on the frame 1 of the card hopper and a steel blade 32 having one end pivotably mounted on the frame. The steel blade is magnetically attracted to the magnetic strip. The other end of the steel blade is attached to a pressure plate 26 resting on the top card in the hopper. When a given number of cards are in the hopper, the steel blade is completely out of contact with the magnetic strip. At this time, the only weight applied to the drive roller is the weight of the cards plus the weight of the pressure plate. As cards are fed from the hopper, the steel blade is lowered into contact with the magnetic strip. The initial contact is adjacent the blade pivot point. As additional cards are fed, the contact area of the blade and spring increases incrementally in a rolling type manner such that the combination of the permanent magnet, steel blade, and pressure plate imparts an increasing downward pressure on the stack of cards to thereby off set the weight decrease resulting from the feeding of cards to provide a fairly uniform weight on the card drive roller which varies within acceptable limits such that reliable card feeding of all of the cards in the hopper is accomplished.

In the above described manner, applicant has pro vided a spring loading system which operates inversely to normal spring loading. That is, normally with an extension spring increased loading would occur as the spring is extended and as above discussed, in many applications this is undesirable. Applicant has provided with his present invention, a system of spring loading which operates exactly opposite to the conventional spring loading mechanisms in that in applicants system, as the spring work length is increased, the pressure decreases.

While in the preferred embodiment, a system was described in which a variance of ounces was achieved and the force applied by the steel blade and magnetic strip not uniform, it will be obvious to those skilled in the art that by altering the width of the elements such as by tapering or by changing the edges that the variance could be reduced and the force be made more uniform if desired. Other methods of varying the attraction force between the two elements such as varying the thickness of the magnetic strip and/or blade along their lengths can also be employed.

Finally, while the inverse blade-magnet loading mechanism has been described in a magnetic card feeding application, it will find application in many other areas where such inverse loading is desired. One obvious application is of course paper and envelope sheet feeding. Accordingly, the description is not intended to limit its use to the card feeding art.

While the invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention.

What is claimed is:

l. A loading mechanism for applying an increasing force to a stack of cards as they are moved through a card hopper such that the total force made up of the force contributed by the cards plus said increasing force to a card feed roller remains substantially constant as the cards are fed from said stack, said loading mechanism comprismg:

a pressure plate in contact with said stack of cards,

and

means connected to said pressure plate for applying said increasing force, including means for producing a magnetic field, with said connected means being forcewise attracted to said means for producing said magnetic field in varying amounts as said cards are fed.

2. The loading mechanism of claim 1 wherein said means connected to said pressure plate is a steel blade and said magnetic means is a permanent magnet strip in magnetic association with said steel blade.

3. The loading mechanism of claim 2 wherein said steel blade is flexible and is magnetically attracted to 5 and contacts said magnetic strip in a rolling manner as said cards are fed such that, with a full hopper of cards, at the beginning of feeding no part of said steel blade is in contact with the magnetic strip and at the end of feeding substantially all of said steel blade is in contact with said magnetic strip.

4. The loading mechanism of claim 2 wherein said steel blade is flexible and is magnetically attracted to and contacts said magnetic strip in a rolling manner as said cards are fed and at the beginning of feeding the area of said steel blade initially in contact with said magnetic strip depends on the height of said stack of cards.

5. The loading mechanism of claim 4 wherein said stack of cards are fed sequentially from the bottom of said stack.

6. A card feed mechanism for applying a substantially uniform force to a card in contact with a card feed roller, comprising:

a card hopper having therein a stack of cards, a pres sure plate applying a varying force to the card in said stack most remote from said card feed roller, and

means connected to said pressure plate for applying said varying force including means for producing a magnetic field with said connected means being force wise attracted to said means for producing said magnetic field in increasing amounts as cards are fed from stack by said card feed roller.

7. The card feed mechanism of claim 6 wherein said means connected to said pressure plate is a steel blade and said magnetic means is a permanent magnet strip in magnetic association with said steel blade.

8. The card feed mechanism of claim 7 wherein said steel blade is flexible and is magnetically attracted to and contacts said magnetic strip in a rolling manner as said cards are fed from said hopper such that at the beginning of the feeding of cards from said hopper, no part of said steel blade is in contact with said magnetic strip and at the end of the feeding of said stack of cards from said hopper, substantially all of said steel blade is in contact with said magnetic strip.

9. The card feed mechanism of claim 7 wherein said steel blade is flexible and is magnetically attracted to and contacts said magnetic strip in a rolling manner as said cards are fed from said hopper and at the beginning of the feeding of said stack of cards the area of said steel blade in contact with said magnetic strip depends on the height of said stack of cards. 

1. A loading mechanism for applying an increasing force to a stack of cards as they are moved through a card hopper such that the total force made up of the force contributed by the cards plus said increasing force to a card feed roller remains substantially constant as the cards are fed from said stack, said loading mechanism comprising: a pressure plate in contact with said stack of cards, and means connected to said pressure plate for applying said increasing force, including means for producing a magnetic field, with said connected means being forcewise attracted to said means for producing said magnetic field in varying amounts as said cards are fed.
 2. The loading mechanism of claim 1 wherein said means connected to said pressure plate is a steel blade and said magnetic means is a permanent magnet strip in magnetic association with said steel blade.
 3. The loading mechanism of claim 2 wherein said steel blade is flexible and is magnetically attracted to and contacts said magnetic strip in a rolling manner as said cards are fed such that, with a full hopper of cards, at the beginning of feeding no part of said steel blade is in contact with the magnetic strip and at the end of feeding substantially all of said steel blade is in contact with said magnetic strip.
 4. The loading mechanism of claim 2 wherein said steel blade is flexible and is magnetically attracted to and contacts said magnetic strip in a rolling manner as said cards are fed and at the beginning of feeding the area of said steel blade initially in contact with said magnetic strip depends on the height of said stack of cards.
 5. The loading mechanism of claim 4 wherein said stack of cards are fed sequentially from the bottom of said stack.
 6. A card feed mechanism for applying a substantially uniform force to a card in contact with a card feed roller, comprising: a card hopper having therein a stack of cards, a pressure plate applying a varying force to the card in said stack most remote from said card feed roller, and means connected to said pressure plate for applying said varying force including means for producing a magnetic field with said connected means being force wise attracted to said means for producing said magnetic field in increasing amounts as cards are Fed from stack by said card feed roller.
 7. The card feed mechanism of claim 6 wherein said means connected to said pressure plate is a steel blade and said magnetic means is a permanent magnet strip in magnetic association with said steel blade.
 8. The card feed mechanism of claim 7 wherein said steel blade is flexible and is magnetically attracted to and contacts said magnetic strip in a rolling manner as said cards are fed from said hopper such that at the beginning of the feeding of cards from said hopper, no part of said steel blade is in contact with said magnetic strip and at the end of the feeding of said stack of cards from said hopper, substantially all of said steel blade is in contact with said magnetic strip.
 9. The card feed mechanism of claim 7 wherein said steel blade is flexible and is magnetically attracted to and contacts said magnetic strip in a rolling manner as said cards are fed from said hopper and at the beginning of the feeding of said stack of cards the area of said steel blade in contact with said magnetic strip depends on the height of said stack of cards. 